I noticed that with my current Sapphire X800 GTO2 card when finding the max GPU overclock in ATITool, as it gets to the maximum overclock it starts to have visible artifacts on the letters and numbers in the 3d display. These are the only artifacts that show up while looking for the max GPU overclock on my card until it gets close to the point where it crashes. It seems that ATITool doesn't detect these kinds of artifacts. Maybe there should be an optional feature to scan that area, too?